The invention relates to perfluoroalkyl substituted antioxidants and their use to impart exceptional antioxidant properties to polymeric substrate which subject to severe environmental conditions. Fluorochemical additives has demonstrated the unique ability to modify the surface properties of polymers by adsorption at the polymer/air interface even when used at very low levels. This has been demonstrated by measurements of reduced wettability and decreased friction. Adsorption may occur at the polymer/air interface during the formation of the polymer surface. There is also evidence that certain fluorinated additive molecules are sufficiently mobile in the solid polymer to reach and repair the surface by diffusion and selective adsorption. Thus, they have the unique ability to self-heal, i.e. the molecules from the interior of the polymer can migrate to and repair an additive deficient surface. Fluorochemicals can inherently retain these unique migrating properties while maintaining the high molecular weight necessary to minimize volatility. This application for fluorochemical antioxidants has not hitherto been described. Because of the high costs of fluorochemicals, the use level of the derived fluorochemical is an important consideration. It is anticipated that the subject fluorinated antioxidants will function as synergists and as minor additives in combination with standard antioxidants. Major use areas are fiber, films, high density polyethylene and automative plastics. Inexpensive butylated hydroxytoluenes are sufficient for many low temperature applications, but when polymers are processed and fabricated at elevated temperatures, less volatile high molecular weight additives which have a lower propensity to discolor are required. 2,4-bis(tert-butyl)-6-(heptafluoropropyl)-phenol has been reported in Bull. Chem. Soc. Jpn, 57 (11), 3361 (1984). Said compound has not been suggested as an antioxidant and it would be much too volatile for use as a high temperature antioxidant in any event.